1. Field of the Invention
The present invention relates to a vacuum gun for a suction device, and more particularly to a vacuum gun used with a hand held portable suction device that is handy and space-saving.
2. Description of Related Art
A suction device provides quick and effective pharyngeal and tracheal suction during multiple types of emergencies. With reference to FIGS. 6 to 9, a conventional suction device is a light and portable, can be operated with one hand and allows the other hand to be free for other important uses. The conventional suction device comprises an adapter (80) and a vacuum gun (60).
The vacuum gun (60) comprises a front piston housing (61), a rear housing (62), a handle (70) and a trigger (71).
A piston (63) with a front face (not numbered) and a rear face (not numbered) is slidably mounted inside the front piston housing (61) to generate a suction force on the adapter (80). A dividing wall (not numbered) is formed between the front piston housing (61) and the rear housing (62). A piston shaft (64) is formed on and extends from the piston (63). A free end of the piston shaft (64) penetrates the dividing wall and extends into the rear housing (62). A drive shaft (not numbered) is formed on the free end of the piston shaft (64), and a transverse drive rod (not numbered) protrudes from the drive shaft. Additionally, a spring (not numbered) is mounted around the piston shaft (64) between the dividing wall and the rear face of the piston to make the piston (63) move forward automatically.
The rear housing (62) has a rear wall (not numbered), a top and a bottom. A drive lever (65) is pivotally mounted inside the rear housing (62) at a middle portion of the drive lever (65) and has two moveable ends (not numbered). A longitudinal slot (not numbered) is formed on one end, and a transverse link pin (not numbered) is installed near the other end. The transverse drive rod on the drive shaft freely slides in the longitudinal slot so the pivotal movement of the drive lever (65) will cause the drive shaft and the piston shaft (64) to move longitudinally inside the vacuum gun (60). The transverse link pin in the other end of the drive lever (65) freely moves in a drive slot formed in an inner end of the trigger (71). Therefore, squeezing the trigger (71) pivots the drive lever (65) that pulls the drive shaft, the piston shaft (64) and the piston (63) toward the rear wall. The piston (63) moves a distance in the front piston housing (61) called piston travel. The physical configuration and limitations on the movement of the piston (63) determine maximum travel. A travel adjustment knob (66) with a 100% and 50% positions is rotatably mounted on an outer surface of the rear wall of the rear housing (62), and an adjusting post (67) is connected to the travel adjustment knob (66). The adjusting post (67) extends toward the piston shaft (64) and is composed of a first stop plate (68) and second stop plate (69) that are longitudinally perpendicular to each other. The first stop plate (68) and second stop plate (69) have different longitudinal lengths to limit the piston travel to 100% and 50% of the maximum travel, respectively. The handle (70) is formed on and extends from the bottom of the rear housing (62) for a user to grip the vacuum gun (60).
To operate the suction device, the trigger (71) of the vacuum gun (80) is squeezed to pivot the drive lever (65). Then the longitudinal slot in the drive lever (65) is drawn backward to make the piston (63) move backward with the drive shaft until the drive shaft reaches the adjusting post (67). Moreover, the drive shaft can be selectively stopped by the first stop plate (68) or the second stop plate (69) at different positions to control the amount of air sucked from the adapter (80). The travel adjustment knob (66) rotates to decide which stop plate (68.69) will limit the movement of the drive and piston shaft (64).
However, the conventional vacuum gun (60) has the following drawbacks.
1. Because the piston shaft (64) is stopped by the first and second stop plates (68, 69), the trigger (71) cannot be squeezed completely when the travel adjustment knob (66) is in the 50% travel position. When the travel adjustment knob (66) is in the 50% travel position, the adjusting post (67) stops the piston shaft (64) at the first top plate (68). This can lead to improper operation of the vacuum gun (60) and cause doubt concerning the operability of the vacuum gun (60).
2. The handle (70) and the trigger (71) protrude out of the rear housing (62) and take a lot of space. Therefore, the vacuum gun (60) is inconvenient to store.
The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional vacuum gun for a suction device.
The main objective of the invention is to provide a vacuum gun for a suction device that is easy to use.
Other advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.